1. Field of the Invention
The present invention is generally related to a tool and method for use thereof for facilitating repair of a severed tendon. More particularly, the present invention is related to a tool and method for use thereof for facilitating retrieval and reattachment of a severed flexor tendon. More specifically, the present invention relates to a tool and method for use thereof for facilitating dilation of a flexor tendon sheath and corresponding pulleys, attachment of a severed flexor tendon thereto, passage of the severed flexor tendon through the flexor tendon sheath and the corresponding pulleys, and reattachment of the severed flexor tendon.
2. Description of the Prior Art
Fingers in the hand are moved by flexor and extensor tendons arising from muscles in the forearm. The mechanism facilitating movement of the fingers using the flexor tendons includes three main components in each of the fingers: 1) the skeleton, including phalanges and corresponding articulations (or interphalangeal joints) between the phalanges; 2) a flexor tendon sheath; and 3) the flexor tendons themselves.
In each finger, two flexor tendons work to flex the proximal and distal interphalangeal joints, namely the flexor digitorum superficialis and the flexor digitorum profundis, respectively. Furthermore, the flexor tendon sheath holds the flexor tendons in close proximity to the phalanges of each finger to ensure that their pull produces immediate movement at the interphalangeal joints. In the absence of the flexor tendon sheaths, the flexor tendons simply “bow-string” and fail to produce the desired joint motion.
The flexor tendon sheath is highly specialized tissue that is anchored to bone and forms a very smooth but tight fibrous tunnel around the flexor tendons. With the flexor tendons surrounded by the flexor tendon sheath, there is a measurable hydrostatic pressure within the substance of the tendons. The flexor tendon sheath is not a uniform fibrous tunnel, but rather, is made of identifiable individual segments. The individual segments that make up the flexor tendon sheath are referred to as pulleys because of the mechanical role they play: i.e., holding the flexor tendons close to the phalanges; preventing “bow-stringing” of the flexor tendons; and ultimately translating pull of the flexor tendons into joint motion.
For decades, surgical repair of severed flexor tendons has proven challenging. When the flexor tendons of a finger are severed, the flexor tendons retract through the flexor tendon sheath. Thus, to facilitate repair thereof, the severed flexor tendons must be passed through the flexor tendon sheath to a repair site. However, the ends of the severed flexor tendons swell, and, in the absence of the flexor tendons, the flexor tendon sheath (including the corresponding pulleys) contracts. Accordingly, passing the severed flexor tendons through the flexor tendon sheath is difficult.
Therefore, there is a need for a tool and method for use thereof for facilitating retrieval and reattachment of a severed flexor tendon. Such a tool and method for use thereof should facilitate one or more of dilation of a flexor tendon sheath and corresponding pulleys, attachment of a severed flexor tendon thereto, passage of the severed flexor tendon through the flexor tendon sheath and the corresponding pulleys, and reattachment of the severed flexor tendon.